So this was ultimately my explanation for Proto Man's unusual behavior a while ago. As mentioned, at the time I was thinking about starting some bad blood between Proto Man and George, but I decided that the whole thing was too out of character for Proto Man, so when I came up with the idea of having a robotic clone of Dr. Wily, I realized I could do the same thing with Proto Man.

After all, it makes sense that Dr. Wily would have attempted to create a robotic clone of Proto Man at some point, why not have it be here? So the original Doc Robot becomes Dark Man and impersonates Proto Man in the fifth game.

But now the question is, did Proto Man ever encounter George in this storyline, or was it Dark Man from the very beginning? It could explain how Proto Man could be fighting Mega Man without leaving Dr. Wily's lab, where he was supposed to be keeping an eye on George.